Collaborative research defines a novel approach to understanding how certain proteins called transcription factors determine which genetic programs will drive cell growth and maturation. The method, called 'Perturb-multiome,' uses CRISPR to knock out the function of individual transcription factors across many blood cells at once. The researchers then perform single-cell analyses on each cell to measure the effects of the editing, including identifying which genes have been turned on or off and which genes are accessible (based on epigenetic markers).